Introducing the Sure Grip Magnetic Powerhead Holder. An innovative new way of attaching powerheads to your aquarium. Now your powerhead can be placed anywhere on the wall of your glass or acrylic aquarium. Offered in two sizes to fit most aquarium applications and compatible with most major brand powerheads. Both the Sure Grip 50 and the Sure Grip 100 come complete with two magnetic housings, eight sticky-backed rubber feet and four different plastic brackets. Dimensions: 1-3/4" L x 3-1/8" W x 3/4" H